fix: Changed bucket policy validation error messages

auth/bucket_policy.go

@@ -16,12 +16,22 @@ package auth
 
 import (
 	"encoding/json"
-	"fmt"
+	"errors"
 	"net/http"
 
 	"github.com/versity/versitygw/s3err"
 )
 
+var (
+	errResourceMismatch = errors.New("Action does not apply to any resource(s) in statement")
+	//lint:ignore ST1005 Reason: This error message is intended for end-user clarity and follows their expectations
+	errInvalidResource = errors.New("Policy has invalid resource")
+	//lint:ignore ST1005 Reason: This error message is intended for end-user clarity and follows their expectations
+	errInvalidPrincipal = errors.New("Invalid principal in policy")
+	//lint:ignore ST1005 Reason: This error message is intended for end-user clarity and follows their expectations
+	errInvalidAction = errors.New("Policy has invalid action")
+)
+
 type BucketPolicy struct {
 	Statement []BucketPolicyItem `json:"Statement"`
 }
@@ -75,11 +85,14 @@ func (bpi *BucketPolicyItem) Validate(bucket string, iam IAMService) error {
 
 	for action := range bpi.Actions {
 		isObjectAction := action.IsObjectAction()
-		if isObjectAction && !containsObjectAction {
-			return fmt.Errorf("unsupported object action '%v' on the specified resources", action)
+		if isObjectAction == nil {
+			break
 		}
-		if !isObjectAction && !containsBucketAction {
-			return fmt.Errorf("unsupported bucket action '%v' on the specified resources", action)
+		if *isObjectAction && !containsObjectAction {
+			return errResourceMismatch
+		}
+		if !*isObjectAction && !containsBucketAction {
+			return errResourceMismatch
 		}
 	}
 
@@ -108,6 +121,11 @@ func ValidatePolicyDocument(policyBin []byte, bucket string, iam IAMService) err
 		return getMalformedPolicyError(err)
 	}
 
+	if len(policy.Statement) == 0 {
+		//lint:ignore ST1005 Reason: This error message is intended for end-user clarity and follows their expectations
+		return getMalformedPolicyError(errors.New("Could not parse the policy: Statement is empty!"))
+	}
+
 	if err := policy.Validate(bucket, iam); err != nil {
 		return getMalformedPolicyError(err)
 	}

auth/bucket_policy_actions.go

@@ -16,7 +16,6 @@ package auth
 
 import (
 	"encoding/json"
-	"fmt"
 	"strings"
 )
 
@@ -119,7 +118,7 @@ var supportedObjectActionList = map[Action]struct{}{
 // Validates Action: it should either wildcard match with supported actions list or be in it
 func (a Action) IsValid() error {
 	if !strings.HasPrefix(string(a), "s3:") {
-		return fmt.Errorf("invalid action: %v", a)
+		return errInvalidAction
 	}
 
 	if a == AllActions {
@@ -134,31 +133,39 @@ func (a Action) IsValid() error {
 			}
 		}
 
-		return fmt.Errorf("invalid wildcard usage: %v prefix is not in the supported actions list", pattern)
+		return errInvalidAction
 	}
 
 	_, found := supportedActionList[a]
 	if !found {
-		return fmt.Errorf("unsupported action: %v", a)
+		return errInvalidAction
 	}
 	return nil
 }
 
+func getBoolPtr(bl bool) *bool {
+	return &bl
+}
+
 // Checks if the action is object action
-func (a Action) IsObjectAction() bool {
+// nil points to 's3:*'
+func (a Action) IsObjectAction() *bool {
+	if a == AllActions {
+		return nil
+	}
 	if a[len(a)-1] == '*' {
 		pattern := strings.TrimSuffix(string(a), "*")
 		for act := range supportedObjectActionList {
 			if strings.HasPrefix(string(act), pattern) {
-				return true
+				return getBoolPtr(true)
 			}
 		}
 
-		return false
+		return getBoolPtr(false)
 	}
 
 	_, found := supportedObjectActionList[a]
-	return found
+	return &found
 }
 
 func (a Action) WildCardMatch(act Action) bool {
@@ -177,7 +184,7 @@ func (a *Actions) UnmarshalJSON(data []byte) error {
 	var err error
 	if err = json.Unmarshal(data, &ss); err == nil {
 		if len(ss) == 0 {
-			return fmt.Errorf("actions can't be empty")
+			return errInvalidAction
 		}
 		*a = make(Actions)
 		for _, s := range ss {
@@ -190,7 +197,7 @@ func (a *Actions) UnmarshalJSON(data []byte) error {
 		var s string
 		if err = json.Unmarshal(data, &s); err == nil {
 			if s == "" {
-				return fmt.Errorf("actions can't be empty")
+				return errInvalidAction
 			}
 			*a = make(Actions)
 			err = a.Add(s)

auth/bucket_policy_effect.go

@@ -30,5 +30,6 @@ func (bpat BucketPolicyAccessType) Validate() error {
 		return nil
 	}
 
-	return fmt.Errorf("invalid effect: %v", bpat)
+	//lint:ignore ST1005 Reason: This error message is intended for end-user clarity and follows their expectations
+	return fmt.Errorf("Invalid effect: %v", bpat)
 }

auth/bucket_policy_principals.go

@@ -16,7 +16,6 @@ package auth
 
 import (
 	"encoding/json"
-	"fmt"
 )
 
 type Principals map[string]struct{}
@@ -37,7 +36,7 @@ func (p *Principals) UnmarshalJSON(data []byte) error {
 
 	if err = json.Unmarshal(data, &ss); err == nil {
 		if len(ss) == 0 {
-			return fmt.Errorf("principals can't be empty")
+			return errInvalidPrincipal
 		}
 		*p = make(Principals)
 		for _, s := range ss {
@@ -46,7 +45,7 @@ func (p *Principals) UnmarshalJSON(data []byte) error {
 		return nil
 	} else if err = json.Unmarshal(data, &s); err == nil {
 		if s == "" {
-			return fmt.Errorf("principals can't be empty")
+			return errInvalidPrincipal
 		}
 		*p = make(Principals)
 		p.Add(s)
@@ -54,7 +53,7 @@ func (p *Principals) UnmarshalJSON(data []byte) error {
 		return nil
 	} else if err = json.Unmarshal(data, &k); err == nil {
 		if k.AWS == "" {
-			return fmt.Errorf("principals can't be empty")
+			return errInvalidPrincipal
 		}
 		*p = make(Principals)
 		p.Add(k.AWS)
@@ -66,7 +65,7 @@ func (p *Principals) UnmarshalJSON(data []byte) error {
 		}
 		if err = json.Unmarshal(data, &sk); err == nil {
 			if len(sk.AWS) == 0 {
-				return fmt.Errorf("principals can't be empty")
+				return errInvalidPrincipal
 			}
 			*p = make(Principals)
 			for _, s := range sk.AWS {
@@ -98,7 +97,7 @@ func (p Principals) Validate(iam IAMService) error {
 		if len(p) == 1 {
 			return nil
 		}
-		return fmt.Errorf("principals should either contain * or user access keys")
+		return errInvalidPrincipal
 	}
 
 	accs, err := CheckIfAccountsExist(p.ToSlice(), iam)
@@ -106,7 +105,7 @@ func (p Principals) Validate(iam IAMService) error {
 		return err
 	}
 	if len(accs) > 0 {
-		return fmt.Errorf("user accounts don't exist: %v", accs)
+		return errInvalidPrincipal
 	}
 
 	return nil

auth/bucket_policy_resources.go

@@ -16,7 +16,6 @@ package auth
 
 import (
 	"encoding/json"
-	"fmt"
 	"strings"
 )
 
@@ -30,7 +29,7 @@ func (r *Resources) UnmarshalJSON(data []byte) error {
 	var err error
 	if err = json.Unmarshal(data, &ss); err == nil {
 		if len(ss) == 0 {
-			return fmt.Errorf("resources can't be empty")
+			return errInvalidResource
 		}
 		*r = make(Resources)
 		for _, s := range ss {
@@ -43,7 +42,7 @@ func (r *Resources) UnmarshalJSON(data []byte) error {
 		var s string
 		if err = json.Unmarshal(data, &s); err == nil {
 			if s == "" {
-				return fmt.Errorf("resources can't be empty")
+				return errInvalidResource
 			}
 			*r = make(Resources)
 			err = r.Add(s)
@@ -60,12 +59,7 @@ func (r *Resources) UnmarshalJSON(data []byte) error {
 func (r Resources) Add(rc string) error {
 	ok, pattern := isValidResource(rc)
 	if !ok {
-		return fmt.Errorf("invalid resource: %v", rc)
-	}
-
-	_, found := r[pattern]
-	if found {
-		return fmt.Errorf("duplicate resource: %v", rc)
+		return errInvalidResource
 	}
 
 	r[pattern] = struct{}{}
@@ -99,7 +93,7 @@ func (r Resources) ContainsBucketPattern() bool {
 func (r Resources) Validate(bucket string) error {
 	for resource := range r {
 		if !strings.HasPrefix(resource, bucket) {
-			return fmt.Errorf("incorrect bucket name in %v", resource)
+			return errInvalidResource
 		}
 	}